1608. Special Array With X Elements Greater Than or Equal X LeetCode Solution

In this guide, you will get 1608. Special Array With X Elements Greater Than or Equal X LeetCode Solution with the best time and space complexity. The solution to Special Array With X Elements Greater Than or Equal X problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.

Table of Contents

  1. Problem Statement
  2. Complexity Analysis
  3. Special Array With X Elements Greater Than or Equal X solution in C++
  4. Special Array With X Elements Greater Than or Equal X solution in Java
  5. Special Array With X Elements Greater Than or Equal X solution in Python
  6. Additional Resources
1608. Special Array With X Elements Greater Than or Equal X LeetCode Solution image

Problem Statement of Special Array With X Elements Greater Than or Equal X

You are given an array nums of non-negative integers. nums is considered special if there exists a number x such that there are exactly x numbers in nums that are greater than or equal to x.
Notice that x does not have to be an element in nums.
Return x if the array is special, otherwise, return -1. It can be proven that if nums is special, the value for x is unique.

Example 1:

Input: nums = [3,5]
Output: 2
Explanation: There are 2 values (3 and 5) that are greater than or equal to 2.

Example 2:

Input: nums = [0,0]
Output: -1
Explanation: No numbers fit the criteria for x.
If x = 0, there should be 0 numbers >= x, but there are 2.
If x = 1, there should be 1 number >= x, but there are 0.
If x = 2, there should be 2 numbers >= x, but there are 0.
x cannot be greater since there are only 2 numbers in nums.

See also  196. Delete Duplicate Emails LeetCode Solution

Example 3:

Input: nums = [0,4,3,0,4]
Output: 3
Explanation: There are 3 values that are greater than or equal to 3.

Constraints:

1 <= nums.length <= 100
0 <= nums[i] <= 1000

Complexity Analysis

  • Time Complexity: O(\texttt{sort})
  • Space Complexity: O(\texttt{sort})

1608. Special Array With X Elements Greater Than or Equal X LeetCode Solution in C++

class Solution {
 public:
  int specialArray(vector<int>& nums) {
    ranges::sort(nums);

    if (nums[0] >= nums.size())
      return nums.size();

    for (int i = 1; i < nums.size(); ++i) {
      const int count = nums.size() - i;
      if (nums[i - 1] < count && nums[i] >= count)
        return count;
    }

    return -1;
  }
};
/* code provided by PROGIEZ */

1608. Special Array With X Elements Greater Than or Equal X LeetCode Solution in Java

class Solution {
  public int specialArray(int[] nums) {
    Arrays.sort(nums);

    if (nums[0] >= nums.length)
      return nums.length;

    for (int i = 1; i < nums.length; ++i) {
      final int count = nums.length - i;
      if (nums[i - 1] < count && nums[i] >= count)
        return count;
    }

    return -1;
  }
}
// code provided by PROGIEZ

1608. Special Array With X Elements Greater Than or Equal X LeetCode Solution in Python

class Solution:
  def specialArray(self, nums: list[int]) -> int:
    nums.sort()

    if nums[0] >= len(nums):
      return len(nums)

    for i, (a, b) in enumerate(itertools.pairwise(nums)):
      count = len(nums) - i - 1
      if a < count and b >= count:
        return count

    return -1
# code by PROGIEZ

Additional Resources

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